Early Dolphins
During the early Miocene (about 20 Ma), echolocation developed in its modern form. Various extinct dolphin-like families flourished. Early dolphins include Kentriodon and Hadrodelphis. These belong to Kentriodontidae, which were small to medium-sized toothed cetaceans with largely symmetrical skulls, and thought likely to include ancestors of some modern species. Kentriodontids date to the late Oligocene to late Miocene. Kentriodontines ate small fish and other nectonic organisms; they are thought to have been active echolocators, and might have formed schools. Diversity, morphology and distribution of fossils appear parallel to some modern species.
Read more about this topic: Evolution Of Cetaceans
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